March 22 (Reuters) - Thailand stocks fell more than 3 percent on Friday to a seven-week low due to forced sales on margin accounts, while other Southeast Asian shares mostly ended weaker on fears over the euro zone economy as Cyprus bailout struggle lingered. Thailand's main stock index fell more than 4 percent in early trade due to forced sales on margin accounts and worries about planned increases to required deposits in cash balance accounts. It ended 3.3 percent weaker at 1,478.97, the lowest since Jan. 31. The fall was nothing to do with fundamentals, said Parin Kitchatornpitak, a senior analyst at KTB Securities. "Several stocks were forced selling after the index fell below the 1,500 mark this morning. This put downward pressure on the market," Kitchatornpitak said. The fall came after the exchange said in a statement it planned to raise guarantees needed in cash balance accounts to at least 20 percent of trading value from 15 percent as part of measures to ease volatility in the stock market. The index, which is still up 6.25 percent this year, has lost 7.5 percent this week after hitting a 19-year high on March 15 as a firmer Thai baht also weighed on sentiment. The bourse suffered a $220.30 million outflow in the first four sessions of the week. Other markets ended weaker on growth concerns in euro zone as Cyprus scrambled to avoid a meltdown of its banking system and a possible exit from the euro. Indonesia fell 1.7 percent to a more than three-week low, Singapore ended 0.3 percent weaker, Vietnam lost 0.4 percent, and Malaysia lost 0.2 percent. For Asian Companies click; For South East Asia Hot Stock reports, click; SOUTHEAST ASIAN STOCK MARKETS Change on day Market Current Prev Close Pct Move TR SE Asia Index* 438.88 442.07 -0.72 Singapore 3258.57 3267.65 -0.28 Kuala Lumpur 1626.89 1630.75 -0.24 Bangkok 1478.97 1529.52 -3.30 Jakarta 4723.16 4802.67 -1.66 Manila 6518.71 6472.98 +0.71 Ho Chi Minh 489.99 491.79 -0.37 Change on year Market Current End prev yr Pct Move TR SE Asia Index* 438.88 424.10 +3.49 Singapore 3258.57 3167.08 +2.89 Kuala Lumpur 1626.89 1688.95 -3.67 Bangkok 1478.97 1391.93 +6.25 Jakarta 4723.16 4316.69 +9.42 Manila 6518.71 5812.73 +12.15 Ho Chi Minh 489.99 413.73 +18.43 * The Thomson Reuters South East Asia Index is a highly representative indicator of stocks listed in Indonesia, Malaysia, the Philippines, Singapore, Thailand and Vietnam.