* Nikkei has gained 2.2 pct for the week
* Gains in U.S. futures raise investors' risk appetite - analyst
* Descente soars after report Itochu raises stake to 40 pct
By Ayai Tomisawa
TOKYO, March 15 (Reuters) - Japan's Nikkei made firm gains on Friday morning as a weaker yen supported exporter stocks, while chip-related companies rose on earnings from Broadcom after the Wall Street close.
The market is focused on the Bank Of Japan's policy meeting. While the BOJ is seen sticking to its assessment that Japan's economy "continues to expand moderately," it may slightly modify the language to reflect heightening external risks, the sources say.
The Nikkei share average gained 1 percent to 21,498.07 in midmorning trade. For the week, the index has been up 2.2 percent so far.
Chipmaker Broadcom Inc's first-quarter profit and revenue forecast beat market estimates, lifting its stock 4.7 percent in extended trading.
The news helped lift shares of Japanese chip-related names, with chip equipment maker Tokyo Electron soaring 3 percent and silicon products maker Sumco Corp rising 1.2 percent.
"Appetite for cyclical stocks is strong as the yen is weak and the earnings in the U.S. chip sector helps the mood," said Nobuhiko Kuramochi, a strategist at Mizuho Securities, adding that gains in U.S. futures, which pointed to a stronger open in Wall Street, are also raising risk appetite.
During Asian trade, Dow e-minis rose 45 points, or 0.2 percent. S&P 500 e-minis were up 4 points, or 0.1 percent and Nasdaq 100 e-minis were up 19.5 points, or 0.3 percent.
The dollar is up 0.1 percent to 111.87 yen, helping exporters rally. Fanuc Corp rose 1.6 percent, Komatsu surged 1.9 percent and Honda Motor Co soared 1.5 percent.
Elsewhere, Descente soared 4.2 percent after the Nikkei reported that trading house Itochu Corp looks to have secured the 40 percent target stake in the sportswear maker, up from about 30 percent.
The broader Topix gained 1.1 percent to 1,604.94, with all of its 33 subsectors in positive territory. Advancing issues outnumbered declining ones 1,740 to 306. (Editing by Sam Holmes)