Lion Capital, a London private equity firm, expects to close its purchase of Salem-based potato-chip maker Kettle Foods this month. Details of the transaction were not disclosed, but reports value the purchase at about $300 million. The chip maker employs more than 300 people in Oregon and 700 worldwide. Lion Capital estimates that Kettle Foods will generate sales of $150 million in 2006 and does not expect a change in Oregon operations. The deal will allow Kettle Foods to increase its distribution of products already found in North America, Costa Rica, Asia, India and Western Europe.