TOKYO -?Japan's central bank cut its economic growth forecasts Thursday and kept interest rates near zero, as the export-reliant nation confronts a strong yen and waning overseas demand.

In its October outlook report, the Bank of Japan forecast the world's No 3 economy to grow 2.1 percent in the year through March 2011 and 1.8 percent the following year. Its July assessment projected growth of 2.6 percent and 1.9 percent respectively.

The weaker US economy was one of the main reasons for the downgrade, said Bank of Japan Gov Masaaki Shirakawa.

The "outlook for the US economy has turned pessimistic from optimistic," Shirakawa said at a press conference, according to Kyodo news agency.

The central bank also blamed the yen, which has risen to near historic highs versus the dollar, and the winding down of government stimulus measures.

Earlier in the day, the Bank of Japan left interest rates untouched and offered new details of a $61 billion asset purchase program intended to spur lending to companies.

In a widely expected decision, the nine-member policy board voted unanimously to keep its key interest rate at zero to 0.1 percent following a one-day meeting. The central bank at its last meeting earlier this month tweaked the interest rate for the first time since December 2008.

The meeting comes as Japan faces growing worries about its recovery, which is struggling in the face of a strong yen, persistent deflation and slowing growth in key overseas markets like the US and China. Recent economic indicators point toward deteriorating exports _ a key driver of Japan's economy _ and slowing industrial output.

Japan last month intervened in currency markets for the first time in more than six years, but the effects were short-lived. Prime Minister Naoto Kan's Cabinet this week approved an extra budget to finance $63 billion in stimulus spending.

For the BOJ's part, its Gov Masaaki Shirakawa announced a "comprehensive monetary easing policy" on October 5 that consisted of the rate cut and a pledge to maintain the zero rate policy until prices start rising again.

It also included the creation of a temporary 5 trillion yen ($61 billion) fund to purchase financial assets such as government securities, commercial paper and corporate bonds in an attempt to stimulate the economy by lowering longer-term interest rates and risk premiums. The central bank will offer another 30 trillion yen through its loan program.

The Bank of Japan outlined details of the program Thursday. It will buy up to 3.5 trillion yen of Japanese government bonds and treasury discount bills. The rest will be used for commercial paper, corporate bonds, exchange-traded funds and Japan real estate investment trusts.

Corporate bonds need at least a BBB rating, which is a lower level than the central bank has previously accepted.

The central bank also moved up its next meeting from November 15-16 to November 4-5, a couple days after a Federal Reserve meeting. Markets expect the Fed to ease monetary policy through a plan to buy Treasurys.

"The change of the policy meeting schedule clearly indicates the (central bank) may react promptly once the Fed's decision has a significant impact on the markets, especially on accelerating the yen's appreciation," said Junko Nishioka, chief economist at RBS Securities Japan, in a note to clients.

"This apparently reflects the BOJ's stance, which continues to be behind the curve."

Investors have been anticipating the Fed would buy between $500 billion and $1 trillion in Treasurys to drive interest rates lower and encourage lending and spending. But a report in The Wall Street Journal said the Fed's bond purchases might amount instead to a few hundred billion dollars over several months, undershooting predictions.

The report helped the dollar climb Wednesday versus the euro and Japanese currency. It was trading above the 81-yen line Thursday after falling into the 80-yen range earlier this week.