* Nikkei's immediate resistance level seen at 23,000 - analyst
* Oil stocks, chip equipment makers attract buying
* Defensive utility, food stocks underperform
* Line soars after broker's upgrade
By Ayai Tomisawa
TOKYO, July 19 (Reuters) - Japan's Nikkei share average gained on Thursday, hovering at a one-month high thanks to a softer yen as well as strong demand for energy, mining and chip equipment makers, though investors were wary of bidding up prices across-the-board given the recent rally.
Oil shares jumped after the Nikkei business daily reported that Japanese oil distributors are preparing to suspend imports of Iranian crude oil in line with U.S. demands, stoking speculation the move would lift procurement costs and bump up oil prices.
The oil and mining sectors were the best performers on the board, with Idemitsu Kosan surging 5.2 percent, Showa Shell rallying 4.7 percent and Cosmo Energy advancing 4.7 percent. Inpex rose 4.6 percent.
The Nikkei climbed 0.4 percent to 22,894.62 in midmorning trade for its fifth day of gains. The benchmark index hit 22,949.32 on Wednesday, the highest level since June 13.
The dollar rose to more than a six-month high of 113.14 yen in the previous session, before shedding 0.1 percent at 112.71 yen.
"The Nikkei's level of 23,000 has become its immediate resistance level, and when the index nears this level, profit-taking occurs," said Yutaka Miura, a senior technical analyst at Mizuho Securities.
Chip equipment makers gained ground after ASML Holding NV , a supplier of equipment to the world's biggest computer chipmakers, reported forecast-beating second-quarter results.
Advantest Corp soared 3.6 percent and Tokyo Electron added 3.0 percent.
Messaging app operator Line Corp soared 4.3 percent after UBS Securities raised its stock rating to 'buy' from 'neutral,' saying that its mobile payment transaction business will likely lead its growth.
Defensive sectors such as utility and food lost ground. Tokyo Gas shed 2.3 percent and Osaka Gas declined 1.3 percent.
Brewer Asahi Group Holdings dropped 1.8 percent and soy sauce maker Kikkoman Corp fell 1.6 percent.
The broader Topix added 0.3 percent to 1,757.04. (Editing by Shri Navaratnam)