March 22 (Reuters) - PSA:
* PSA eyes closure of research and development activities at Garenne-Colombes, but will keep sales/after-sales business at site -trade unions
* 1,650 engineering staff at Garenne site to relocate to other sites near Paris - trade unions
* PSA planning to invest extra 60 million euros ($65 million) at Carrieres-sous-Poissy site near Paris - trade unions
* PSA announced earlier in March deal to buy Opel from GM
($1 = 0.9269 euros) Further company coverage: